Skip to navigationSkip to main contentSkip to right columnADVERTISEMENTBen Gran, The Motley FoolSat, June 13, 2026 at 9:45 AM GMT+2 5 min readAs of this writing on June 10, a new round of U.S. military strikes in the Iran conflict has driven up the price of oil. Higher oil prices mean higher prices at the gas pump. And in an economy where many Americans already feel pressured by high costs of living, that could lead to some changes in how people spend their discretionary income.Some retail stocks are more vulnerable than others to high gasoline prices. Retail sector stocks in general are struggling in 2026. So far this year, Walmart (NASDAQ: WMT) and Costco (NASDAQ: COST) are both strongly outperforming the S&P Retail Select Industry Index, but only Costco is outperforming the S&P 500 index:Missed Nvidia in 2009? This Rare Signal Is Flashing Again. In 2009, a "Double Down" signal flashed for a little-known chipmaker called Nvidia. For the first time in years, that same "Total Conviction" signal is flashing for a company 1/100th the size of Nvidia. Continue »WMT Total Return Level data by YCharts.Costco shares have delivered slightly higher returns than Walmart stock in 2026. And if gas prices stay high, that outperformance is likely to continue. Costco might be better positioned than any other retailer to keep thriving even if gas prices spike again.Let's look at a few reasons why Costco could be a better buy than Walmart.Walmart customers are cutting back on gasWalmart and Costco both sell gas. So on that basic level, both retailers will keep earning revenue from gasoline even if gas prices stay higher for longer. But customers seem to be reacting to high gas prices in a way that's more troubling for Walmart's business.On May 21, during the company's most recent earnings call, Walmart's chief financial officer John David Rainey said that although the retailer's higher-income customers are still spending "with confidence," lower-income customers are "more budget-conscious."As part of that trend, Rainey shared a surprising statistic: Walmart fuel-center customers are now buying an average of less than 10 gallons of gas per visit. That's the lowest level since 2022.It's a bad sign, indicating that Walmart shoppers are being hit hard by high gas prices. If people are still topping up their tanks at Walmart gas pumps but having to cut back on gas, that could mean they're tapped out and ready to pull back on other consumer discretionary spending. That could lead to less foot traffic in Walmart stores.Costco: Record-breaking gasoline salesGasoline sales make up a significant portion of Costco's revenue -- about 10% of total net sales, according to the 2025 annual report. But the recent spike in gas prices has driven Costco's gas sales even higher than usual.Terms and Privacy PolicyPrivacy & Cookie SettingsMore Info